1. Field of the Disclosure
The present disclosure relates to a process for recycling ore in the chloride process, and in particular to an improved process for reducing silica-containing gangue from the recycled ore stream.
2. Background of the Disclosure
In a continuous process for producing pigmentary titanium dioxide (TiO2), titanium-containing ore, coke and chlorine are reacted in a chlorination reactor, typically a fluidized bed reactor, at temperatures ranging from about 900 to about 1600 C. Discharged from the reactor are gaseous volatile metal chlorides, in combination with other ingredients, such as, unreacted titanium dioxide (TiO2), silica-containing gangue, and other components comprising coke that are entrained in the discharge gases. This stream, after separation of the gaseous volatile metal chlorides, may then be returned to the reactor. However, presence of the silica-containing gangue in the recycle stream may cause gangue build-up in the reactor that results in more blow-over and eventual ore loss.
Previous efforts to minimize unreacted titanium dioxide ore losses in the chlorinator have focused on capturing all ore and gangue solids and feeding them back into the chlorinator. However, this increases the gangue concentration in the chlorinator and the proportion of blow-over of solids leading to titanium dioxide yield loss.
A need exists for a process whereby the silica-containing gangue present in the solids in the discharge stream is reduced to minimize ore loss.